1. Field of the Invention
The present invention generally relates to multi-position switches and, more particularly, is concerned with a switch inhibitor assembly for inhibiting movement of an actuator of a multi-position switch to a predetermined one of the multiple positions of the switch.
2. Description of the Prior Art
A passive infrared detection system typically includes a heat sensor, a lens for focusing heat energy on the heat sensor, and an electrical mechanism operatively associated with the heat sensor for providing a detection signal when the heat sensor detects a change of temperature, as for example, caused by the body heat of a passing intruder. One common example of a passive infrared detection system incorporates a pyroelectric detector as the heat sensor.
Thus, the detection system works on the principle of detecting the radiant or heat energy emitted by an object, such as the body of the person, moving across the field or fields of view of the heat sensor and the lens of the detection system. To function properly the detection system must be capable of distinguishing between the moving object and a stationary object also emitting infrared radiation. To accomplish this the system is designed to respond to a change in the level of radiation received so that only the moving object will be detected.
The detection system typically employs a multi-position electrical switch, such as a three-position switch, for controlling the various modes of operation of the system, such as OFF, AUTO and ON. The normally desired operational mode of the detection system is the AUTO mode in which, until an intruder is detected, the electrical mechanism of the system assumes an inactive state during which energy consumption is minimized. By contrast, when the detection system is in the ON mode, the electrical mechanism of the system overrides dependence upon detecting an intruder and instead continuously assumes an active state in which energy consumption is elevated, resulting in a wasteful use of expensive electrical energy. Frequently, the switch actuator is inadvertently moved to the ON position, instead of the AUTO position, resulting in continuing high energy consumption by the system until the condition is discovered.
Consequently, a need exists for a device to inhibit movement of the switch actuator to the ON position and thereby prevent unintended operation of the detection system in the continuous or override ON mode.